Arm construction for routers



-Maly- 12, 1959 T. c. MANN ARM CONSTRUCTION FOR ROUTERS 2 Sheets-Sheet 1 Filed July 18, 1957 :mnmui mavsm-rok adore C Q'YLqm Th e , Filed July 18, 1957 y 1959 T. c. MANN 2,886,079

ARM CONSTRUCTION FOR ROUTERS 2 Sheet-Sheet 2 Wok,

omey 2,886,079 p ARM CONSTRUCTION non omans Theodore Mann; Beloit, Wis.,. assignor to- Ekstrom- Carlson-i l:($0,,Rudder-11,111., acorporation of Illinois.

. Application lli ly 18*, 195-7, SerialNo; 672,720

t 61- Glaims. (Cl-1 144-136) This: invention relates-to routers and, more particularly, to double arm routers in. which an inner arm is pivotally connected: ationev end to. a base to swing about a first vertical; axis? and anouter arm ispivotally connected at one end to the free end of the inner arm to swing; about a second verticali axis; Insuch routers, aspindle. for a cutting-,t'ool is supportedcon the free end of the outer arm to turn about a third vertical axis.

Thewgeneral object of the invention is to provide in a router of the above character a novel means for locating the three axesrelative. to each other so that all three are exactly parallel and-this without requiring extreme accuracy in the: construction: and assembly of. the. pivotal connections; t A more:detailedi object'isto divide each'arm into two sections wliich are joinedby ahorizontal pivot permitting the-sectionsitolbe' turned. relative to each? other to bring theuaxes; at..each end of; the arm into parallelisrnand to clamp :thesections in thepselected angular position. The inventionalso; resides intheconstruction and arrangement of the: particular "means for turning the sections about the. pivot and clamping the sections together. i

Othen'objects and advantages of the invention will be- Patented. May 12, 1959 arm projects in between the legs: Averticalshaft 28 extends. through-.theouter arm; along the axis. h. and the ends of thist shaft. project into.the.legs. 27 wheretheyare journaled byt conical bearings 29. (see Fig. 4). Axial thrust bearings; 30 are disposedbetween each leg27 and the. outen. arm 12. and. the legs are drawn tightlyagainst the .outenraces. 3 1. of. these. bearingsby nuts 32 threaded ontov the endsof the shaft28. to prevent axial shifting. of the outer: arm during service use. i

With the. foregoing arrangement, the arms. 10- and. 12 may. be swung. about their. respective axesa and-b to traverse the :cutter. 13: around the periphery of a workpiece suitably. supported beneath. thecutter. Such swinging of the/armsmay be effectedmanually and, for this purpose, handles 33,. aresupported by bars 34 which are projected. forwardly from thetsides oftheouter arm..

According. to. the present invention, the parts of the router. are. constructed and arranged. in. a novel manner so thatthe axes a, b'= and 0 may easily be made to parallel each-other precisely Without the necessity. of extreme. accuracy. inthe formationzand assembly of the. pivotal joints for-thelarms.10..and..12;. To these ends, theinner armis. formed by sections and 36 and the. outer arm by sec; tions s37. and. 38. and the. two sections. of each. arm are joinedbya connection .which permits one section. to. be

turned relative. to the other about a, horizontal axis. to.

come; apparent from. the following detailed description takentin.connectionxwith the-accompanying drawings, in which:--

Figured; is .a fragmentary elevation of a router: embodyingtthenovel arrangement of the presentinvention,,parts being: broken away and shown in section;

Fig; 2 is; an enlarged sectional view taken along the line2.-2win:Fig; l.

Fig. 3 is. a fragmentary. planview of the router, parts beiugrbroken away andlshown in section.

Fig: 4lisran enlarged fragmentary sectional View taken along .the. line. 4-4 in Fig. 1.

Fig. 5 isan enlarged sectional view taken. along the. line. 5 -5 in Fig. l.

Fig. 6 is anvenlarged. fragmentary sectional view taken along the:line6r6 in Eigi 2;

As shown in the drawings: for purposes of illustration,- the invention is embodied in a double arm router comprising an: elongated horizontal inner arm lo pivotally mounted at oneend on a. base 11 to swing about a vertical axis a and pivotally connected at the other end to an elongated'outer arm 12 whereby the outer arm may swing relative to the inner arm about a second vertical axis 12. A cutting'tool 13 is supported on the spindle of a motor 14'torotate abourathird' vertical axis c and the motor slides up and down in Ways 15 (Fig. 3) on the free end of the outer arm. Such sliding is elfected by a hydraulic piston and cylinder type motor 16 which is mounted on the outer arm and is connected to the motor 14 through a bar 17 (Fig. 1). When the cutter 13 is lowered, it projects through a bushing 18 which is on a bracket 19 projecting forwardly from a vertical slide 20. The latter is adjustable in ways 21 (Fig. 3) by a screw 22 so that the bushing may be set at selected heights.

To form the pivotal mounting of the inner arm 10, a

bring. the. axis. on. one. section. parallel. to the axis on the. othersection; Each. connection comprises a pivot 32 which joins the two arm sections .forrelative turning and a meansfor locking the. sections in the angular position in which the axes rare parallel.

In thepresentinvention, vertical surfaces. 40.are ma-. chinedon the adjacent. ends of the sections 37 and 38 of the outer. arm. 1 2..and. these surfacesabut. against each other. A. horizontal. pin projects. into each of. the sections at theirmachined. ends. and near the top. of the arm and is. journaled. therein to constitutethe pivot 39 of the connection betweenthe sections. Thus, the pin 39 definesa horizontal. axisd about which the: section 38 may be turned relative. to the section 37.

The means for adjusting the angular position of the arm section 38 relative to the section 37 includes a second. pin 41 which=is spaced below and parallels the pin 39. One end of. the pin 41 is received snugly in a hole 42 in the machined endoftthe. section 37 while the otherend oftthe pin projectsintoa laterally enlargedxhole 43 (see Fig. 2). inwtheabuttingaend of the section 38. The enlargement of. the.hole.43 permits limited swinging of the section 38 about theaxis d. Such iswinging isxefiected:hereinbyttwo -screws.44.which are threaded into opposite sides ofthe arm section 38v and abut againstthe sides of. the pin 41.

By backingwolf one. screw. 44 andtightening the other; thesectionwfiS. may: be turned'aboutthe axis 0. untiLthe axisc is parallel: tothe axis b. The two sections 37 and 3.8 ..are.clampedio etherin the adjusted position bylbolts 45 which project through holes 46 (Fig. 6) in the section 37 and are threaded into the section 38, the holes 46 being enlarged to permit the relative turning of the sections to bring the axes b and c into parallelism. A similar connection joins the sections 35 and 36 of the inner arm .10, the corresponding parts of this connection being indicated by the same but primed reference characters.

It will be observed that the axes a, b and 0 may be made to parallel each other simply by loosening the bolts 45 and 45 and adjusting the screws 44 and 44'. There need be no extreme accuracy in journaling the arms and 12 in the bearings 26, 29 and 30. With the present invention, it has been possible to aline the axes so accurately as to havethe cutter 13 maintain tolerances of several thousandths of an inch even though the arms 10 and 12 are four or five feet long. Moreover, the invention permitsthe bearings 30 to be clamped tightly in-place to practically eliminate end play of the shaft 28 and thus maintain the accurate location of'the axis c relative to the axis b.

I claim asmy invention:

1. In a router, the combination of, a first horizontal arm section, means supporting said arm section to turn about a first vertical axis disposed adjacent-one end of the section, a second horizontal arm section having one end abutting'against the free end of said first section, a spindle rotatably supported on the otherend of said second section to turn about a second vertical axis, and a connection joining the abutting ends of said sections, said connection comprising a pivot joining said second section to said first section to swing relative to the latter about a horizontal axis, two screws laterally spaced from said pivot and threaded into opposite sides of one of said sections to abut against a part of the other section on opposite sides thereof, whereby threading said screws turns one section relative to the other about said pivot, one of said sections having a plurality of holes extending longitudinally of the section, and a plurality of bolts smaller than said holes projecting through the holes and threaded into the other'section to permit one section to be turned relative to the other to locate said axes parallel to each other, said bolts when tightened clamping said sections in a selected angular position.

2. In a router, the combination of, a first horizontal arm section, means supporting said arm section to" turnabout a first vertical axis disposed adjacent one end of the section, a second horizontal arm sectionhaving one endabutting against the free end of said first section, a spindle rotatably supported on the other end of said second section to turn about a second vertical axis, and a connection joining the abutting ends of said sections, said connection comprising a pivot joining said second section to said first section to swing relative to the latter about a horizontal axis, means for turning said second section about said pivot to locate said second axis parallel to said first axis, one of said sections having a plurality of holes extending longitudinally of the section, and a plurality of bolts smaller than said holes projecting through the holes and threaded into the other section to permit said second section to be turned about said pivot, said bolts when tightened clamping said sections in a selected angular position.

3. A router comprising a base, an elongated inner arm pivotally connected at one end to said base to swing about a first vertical axis, an elongated outer arm pivotally connected at one end to the free end of said inner arm to swing relative thereto about a second vertical axis, a spindle rotatably supported on the other end of said outer arm to turn about a third vertical axis, each of said arms being formed by two sections having vertical surfaces abutting against each other, and two connections, one joining the abutting surfaces of the sections of each of said arms, each of said connections comprising a pivot joining the corresponding'sections to swing relative to each other about a horizontal axis, two screws laterally spaced from said pivot and threaded into opposite sides of one of said sections to abut against a part of the other section on opposite sides thereof, whereby threading said screws turns one section relative to the other about said pivot, and means for clamping said sections in a selected angular position.

4. In a router, the combination of, a first horizontal arm section, means supporting said arm section to turn about a first vertical axis disposed adjacent one end of the section, a second horizontal arm section having one end abutting against the free end of said first section, a spindle rotatably supported on the other end of said second section to turn about a second vertical axis, and a connection joining the abutting ends of said sections, said connection comprising a pivot joining said second section to said first section to swing relative to the latter about a horizontal axis, two screws laterally spaced from said pivot and threaded into opposite sides of one of said sections to abut against a part of the other section on opposite sides thereof, whereby threading said screws turns one section relative to the other about said pivot, and means for clamping said sections in a selected angular position.

5. A router comprising a base, an elongated inner arm pivotally connected at one end to said base to swing about a first vertical axis, an elongated outer arm pivotally con nected at one end to the free end of said inner arm to swing relative thereto about a second vertical axis, a

spindle rotatably supported on the other end of said outer arm to turn about. a third vertical axis, each of said arms being formed by two sections having vertical surfaces abutting against each other, and two connections, one joining the abutting surfaces of the sections of each of said arms, each of said connections comprising a pivot joining the corresponding sections to swing relative to each other about a horizontal axis and means for turning said sections relatively about said pivot and clamping the same in a selected angular position, whereby the two sections of each arm may be adjusted relative to each other to make all of said axes parallel to each other. I

6. In a router, the combination of, a first horizontal anm section, means supporting said arm section to .turn about a first vertical axis disposed adjacent .one end of the section, a second horizontal arm section having one end abutting against the free end of said first'section, a spindle rotatably supported on the other end of said second section to turn about a second vertical axis, a connection joining the abutting ends of said sections, said connection comprising a pivot joining said second section to said first section to turn relative to the latter about a horizontal axis extending longitudinally of said sections, a threaded member laterally spaced from said pivot and threaded transversely into one of said sections to act against the other section and turn one section relative to the other about said pivot thereby to dispose said second axis exactly parallel to said first axis, and separate means for clamping said sections in a selected angular position.

References Cited in the file of this patent UNITED STATES PATENTS Mann Nov. 15, 1955 

